Aquaforest Mg TestPro kit

[Hunter399]

I bought an Aquaforest TestPro kit today for Mg and it is missing the measuring spoon for the C-Mg powder reagent. Anyone know what the measurement is of the spoon is or know if any other spoons will work? Redsea for example

 

[120reefkeeper]

I can check this when I get home in the morning. I'll measure out the amount on a scale and see if it's close or the same. [emoji6]

 

[JimWelsh]

Enough to see the color of the dye in the solution.

 

[Hunter399]

Awesome thanks for looking into it!

 

[Hunter399]

Enough to see the color of the dye in the solution.

You think any variance in additive would throw off the test? As your using very fine drops to slowly turn the color?

 

[JimWelsh]

You think any variance in additive would throw off the test? As your using very fine drops to slowly turn the color?

In general, with calcium and magnesium tests, the powder that you add with a scoop is an indicator dye mixed with some inert salt, such as NaCl or KCl. The only real requirement is to add enough of the dye to be able to see the color change. The exact amount of the dye used is not really important (within reason). If you add 100 scoops worth, then that might affect the test results, but let's not get silly.

 

[Randy Holmes-Farley Verified Community Expert]

To expand on what Jim said, the purpose of the dye is to bind, and give a different color, in the presence of calcium or magnesium.

The liquid you add drop wise is an even stronger calcium or magnesium binder that first binds calcium or magnesium free in solution, then, as you add more, it rips away the Ca/Mg from the colored molecule, changing its color. When you have added enough of the dropwise titrant to bind every calcium or magnesium, then the colored dye won't have any left, and you see the color change. So the exact amount of the dye doesn't matter except as it allows you to see the color change. It is the amount of the other liquid added that is critical, and the number of calcium ions equals the number of strong binders you added to get to the endpoint.